Bartender, Beware: Squeezing Limes Can Cause 'Margarita Burn'

Just ask Justin Fehntrich, who developed second-degree burns on his hand after spending a sunny afternoon squeezing limes for margaritas last month. The "margarita burn" phenomenon, known as phytophotodermatitis, occurs when a person gets a compound called psoralen on his or her skin, said Dr. Doris Day, a dermatologist at Lenox Hill Hospital in New York City. Once activated, it makes the skin "exquisitely sensitive" to light, she told Live Science.